separate pre-processing, add callback parameter to push/pop in python API

src/opt/opt_mux.h

@@ -0,0 +1,32 @@
+/*++
+Copyright (c) 2021 Microsoft Corporation
+
+Module Name:
+
+    opt_mux.h
+
+Abstract:
+   
+    Find mutexes - at most 1 constraints and modify soft constraints and bounds.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2022-04-11
+
+--*/
+
+#pragma once
+
+#include "opt/maxsmt.h"
+
+namespace opt {
+
+    class mux {
+        ast_manager&     m;
+        solver&          s;
+
+    public:
+        mux(solver& s);
+        lbool operator()(vector<soft>& soft, rational& bound);
+    };
+};